This invention relates generally to batteries and relates, more particularly, to the structure and methods of manufacture of rechargeable solid-state thin-film batteries.
The type of rechargeable battery with which this invention is concerned includes a thin-film cathode, a thin-film lithium anode and a thin-film electrolyte disposed between the cathode and anode. A battery of this class is distinguishable from lithium batteries which utilize a solid polymer or lithium ion technology during construction in that it is a completely solid-state device. An example of a thin-film battery of the class with which this invention is concerned is described in application Ser. No. 07/921,528, now abandoned, having the same assignee as the instant invention and whose disclosure is incorporated herein by reference.
Heretofore, batteries such as those described in the referenced application have been produced on a relatively small scale, i.e. typically having a total area (in plan) of a few square centimeters and having a total thickness within the range of between six to eight micrometers (.mu.m), yet have been found to possess a relatively high energy capacity, i.e. about 120 .mu.Ah/cm.sup.2 -.mu.m of cathode volume. To date, however, these batteries have been manufactured with techniques involving time-consuming batch type deposition processes and are not very large for applications requiring high power. For example, a single substrate, such as a glass microscope slide, is sequentially coated (with appropriate masking) with vanadium by dc magnetron sputtering, with V.sub.2 O.sub.5 by reactive dc magnetron sputtering, with a lithium phosphorous oxynitride electrolyte by reactive rf sputtering, and with lithium by evaporation. The resulting cell is then commonly coated with a thin-film protective layer, thus ending a total time of construction (or time of deposition) of about twenty-four hours for a single cell.
It is an object of the present invention to provide a new and improved method of manufacturing a thin-film lithium battery of the aforedescribed class in a relatively short period of time and a battery structure manufactured in accordance with the method.
One more object of the present invention is to provide such a method wherein the construction of a battery of the aforedescribed class can be scaled up to any of a broad range of sizes and/or capacities to take advantage of the potentially high energy density of this class of battery.
Still one more object is to provide such a method which may be employed to manufacture batteries in large quantities.
Another object of the present invention is to provide such a method which accommodates the construction of a very compact, high capacity battery suited for use in high power applications.
Still another object of the present invention is to provide such a method which accommodates the winding of a layup of thin-film battery components into a spiral configuration and accommodates the build up of thin-film battery components onto a foundation, e.g. substrate support surface, having any of a number of shapes.
Yet another object of the present invention is to provide such a battery having a layup of thin-film components which are wound in a spiral configuration.
A further object of the present invention is to provide such a battery having a layup of thin-film components which are built up upon a substrate support surface having any of a number of various shapes.
A still further object of the present invention is to provide a system with which the method of the invention can be carried out.